This guide covers the comprehensive procedure for changing filter elements on our industrial generator units. Performing this maintenance regularly ensures your air quality remains high and protects the generator from sediment and calcification buildup.
🛠️ Tools & Supplies Needed
New Filter Elements
New O-Rings (if applicable to your unit)
Strap Wrench (for tight filter bowls)
Rubber Mallet (for stuck bowls)
Clean rags and mild cleaning solution
Silicone grease (optional, for O-ring seating)
Phase 1: Safety & Depressurization
⚠️ CRITICAL WARNING: The filter system operates under high pressure. You must depressurize the specific bank of filters you are servicing before attempting to remove any components. Failure to do so can result in injury or equipment damage.
Turn Generator Off: Switch the generator unit to the "OFF" position.
Isolate Air Supply: Locate the inlet air valve feeding the generator and close it completely to stop the flow of new air.
Locate Relief Valve: Find the pressure relief valve located immediately after your bank of filters. It should be marked with a service tag.
Depressurize: Open the relief valve to vent the trapped pressure. You may hear a hissing sound as the air escapes; wait for this to stop completely.
Secure the Valve: Leave this relief valve in the OPEN position for the entire duration of the maintenance. This ensures pressure cannot build up accidentally while you are working.
Phase 2: Disassembly & Cleaning
Once the system is verified safe (0 PSI), proceed with removing the housing bowls.
Remove Filter Bowls:
Grip: Hold the main body of the bowl. Do not grip by the drain mechanism, as it is fragile and can snap.
Unscrew: Turn the bowl counter-clockwise.
Stuck Bowl? If the bowl is hand-tight and won't budge, use a strap wrench. Place the strap near the top of the bowl (closest to the threads) to avoid crushing the body.
💡 Technician Tip: Baked-on O-Rings
Sometimes the rubber O-ring inside the filter head can "bake" onto the bowl over time, creating a seal that feels like it's glued shut. If a strap wrench isn't working, try gently tapping around the rim of the bowl with a rubber mallet to break the bond before trying to unscrew it again.
Separate Drains: Remove the auto-drain mechanism from the bottom of the bowl.
Clean Components: Wash the bowls and drains thoroughly.
Goal: You want to remove all sediment, sludge, or calcification.
Inspect: Check the floats inside the drains. If a float is sticking or looks corroded, replace the drain immediately. A failed drain can flood your generator.
Pre-Assembly: Reattach the cleaned/new drains to the filter bowls and set them aside in a clean area.
Phase 3: Element Replacement
Remove Old Elements: Unscrew or pull the old filter elements from the filter head. Discard them according to your facility's waste protocols.
Inspect O-Rings: *
Check the O-ring seals inside the filter head.
Rule of Thumb: If your unit uses O-rings, we highly recommend changing them every time you change the filter. Old O-rings flatten out and are the #1 cause of leaks after service.
Tip: Ensure the new O-ring is seated in the groove correctly. A pinch here will cause a leak later.
Install New Elements: Insert the new filter element. Ensure it is seated firmly.
Reinstall Bowls: Screw the filter bowls (with drains attached) back onto the filter heads. Hand-tighten firmly. Do not use a wrench to tighten, as this makes them impossible to remove next time.
Phase 4: Restart & Verification
Follow this specific sequence to bring the unit back online without shocking the system.
Close Relief Valve: Return the manual relief valve (the one with the service tag) to the CLOSED position.
Pressurize Slowly: Go to your inlet air valve. Open it VERY SLOWLY.
Why? Rushing air into an empty system can damage internal components ("water hammer" effect).
Leak Check: As the system reaches pressure, listen and look for leaks around the filter bowls.
Note: If you hear hissing, close the inlet immediately and check your O-ring seating.
Power On: Once the system is holding pressure, turn the generator back to the "ON" position.
Phase 5: System Acknowledgement
The controller needs to know that maintenance has been performed to reset the service timers.
Navigate to the Maintenance/Filter menu on the controller screen.
Select Filter Change.
Enter Password: If the system prompts you for a security code, enter 6557.
❓ Troubleshooting
Leak at the bowl threads?
This is usually caused by a pinched O-ring or debris in the threads. Depressurize the system again, remove the bowl, wipe the threads clean, and reseat the O-ring.